Chemical consequences of the nuclear reactions 58Fe(n,γ)59Fe and 57Co(EC)57Fe in soluble Prussian Blue

Abstract

KFe[Fe(CN)₆],H₂O was prepared with ⁵⁸Fe in either the cation or the complex, and both samples were neutron-irradiated and analysed for free and complexed ⁵⁹Fe. Parallel experiments were performed on K₄[Fe(CN)₆],3H₂O. In Prussian Blue the retention in the hexacyano-complex is ca. 5% and can be increased only slightly by annealing, whereas it is ca. 20% in the simple hexacyanide and increases to 30% on annealing. It is suggested that the low retention in Prussian Blue is due to competition between recoil ⁵⁹Fe and inactive Fe³⁺ for re-formation of the complex.

Mössbauer experiments were performed on KFe[Fe(CN)₆],H₂O doped with ⁵⁷Co as cation or in the complex. The spectra showed that ⁵⁷Fe formed by the ⁵⁷Co(EC)⁵⁷Fe process in the cationic ⁵⁷Co does not enter the complex. ⁵⁷Fe formed from [⁵⁷Co(CN)₆] however appears principally in a different complex species, probably losing a CN^– ligand to form a pentacyanide.